Commonly used extraction bags include tea bags for black teas, green teas, herbal teas, and other teas and extraction bags containing dried products such as dried small sardine and dried bonito for preparing stock. Such an extraction bag includes: a bag body having a flat, tetrahedral, or other shape and made of a water-permeable filter sheet such as a nonwoven fabric sheet; an extractable material, such as tea leaves, packed in the bag body; and a hanging string with a tag that is attached to the outer surface of the bag body.
In one known extraction bag sheet used to manufacture such extraction bags, hanging strings each having a tag for a single extraction bag are disposed on a strip-like water-permeable filter sheet at predetermined intervals in the lengthwise direction of the sheet (Patent Document 1). In another known extraction bag sheet that is designed to be manufactured with improved productivity, tags are disposed on a strip-like water-permeable filter sheet at predetermined intervals in the lengthwise direction of the sheet, and a long string is disposed in a specific convolution pattern so as to be placed on each tag (Patent Document 2).    [Patent Document 1] Japanese Patent Application Laid-Open No. Hei 10-157709    [Patent Document 2] Published Japanese Translation of PCT International Application No. 2006-510550